The approval of the Roe Highway extension has prompted anger among traditional owners.

ABC News: Andrew O'Connor

The West Australian Government has been accused of misrepresenting the views of traditional owners in relation to the development of the Roe Highway extension.

Indigenous people who consider North and Bibra Lakes in Perth's south to be sacred say the proposed road did not receive majority support in consultations in 2010 and 2012.

The Main Roads website states "Roe 8 has received heritage consent from the Minister of Aboriginal Affairs" and refers to the "support and contribution of the Traditional Owners throughout the heritage survey program conducted between 2010 and 2012".

But the surveys from 2010 and in 2012 show a majority of those consulted opposed Roe 8.

The WA Government has said the cultural heritage assessment reports were carried out by an independent heritage consultancy and are confidential.

A copy of the report on the 2010 consultation, obtained by the ABC, reveals 54 traditional owners were consulted, with 26 "expressing approval" and 28 "not in favour".

A majority of those who expressed opposition to the road said they still wanted to be fully consulted on the progress of the development, while others sought to drop out of the process altogether.

It seems like it was done and dusted when they spoke to us.

Reverend Sealin Garlett

A report on the second consultation, in 2012, shows that of the 45 people surveyed, most "remained opposed to the highway extension plans".

The process sparked concern that some supporters of the road who were consulted had no right to participate in the voting.

Reverend Sealin Garlett, who was involved in both consultations, described the process as "absolutely disappointing".

"We made it very clear, the situation on our part, but the views on our part have been seen as irrelevant," Reverend Garlett said.

"They came to listen and we thought that was good but this was going to be the outcome that they had drawn up. It seems like it was done and dusted when they spoke to us."

Waugal legend

Indigenous people have long considered the North Lake and Bibra Lake area to be sacred.

A Heritage Assessment of North Lake/Bibra Lake Region, carried out in 1987 for the proposed Roe extension, spoke about the legend of a giant serpent called a Waugal - also known as Wagal, Wagyl or Uocol.

Not happy with people who might have gone and ticked it off who don't actually have the knowledge.

Gail Beck, South West Aboriginal Land and Sea Council

"The legend that a Waugal inhabits these lakes and maintains the flow of springs that feed them is widely known," the report said.

Back in 1885, early WA settler George Fletcher Moore wrote of the Waugal as a "huge winged serpent" who lived in deep dark waters.

More than a hundred years after that account, the lakes area was still being used by Aboriginal people.

The 1987 heritage report identified "recent" Aboriginal camping areas close to the north-eastern edge of Bibra Lake, as well as along the southern shore.

Gail Beck, regional development manager with the South West Aboriginal Land and Sea Council, worked on Melville's Aboriginal history.

Although she is not a traditional owner, her expertise has been called on during consultations about the road over many years.

"This is an extremely important site, and what we've been saying from the get go is if you destroy the web of life there, the effects will be shocking, the lake systems will start drying up," Ms Beck said.

"Those sites there also connect to other countries, not overseas obviously, but other countries.

"So it's killing off all the songlines."

Highway name 'slap in the face'

Ms Beck said Indigenous people remained opposed to the Roe, believing that some who had a say in the consultations had not been entitled to do so.

"Not happy with people who might have gone and ticked it off who don't actually have the knowledge. Because quite often with these heritage surveys ... they go along because they're getting paid," she said.

"The State Government tends to pick the 'yes' people.

We're very concerned that the voices of the traditional owners are being silenced in this debate.

Greens MLC Lynn MacLaren

"The biggest problem is the Department of Aboriginal Affairs, they know how important that site is, but the minister gave it the tick off."

Ms Beck said there was serious concern about the name of the road itself.

"John Septimus Roe was one of the leaders that led the redcoats down to Pinjarra to do the Pinjarra massacre. Some call it a battle, but it was a massacre," she said.

"And it's again just another slap in the face to Noongar people that they're going to put this freeway named after a man that destroyed a whole group of people.

"It's just bad taste, bad taste."

Minister, Main Roads defend project

Aboriginal Affairs Minister Peter Collier said there was extensive consultation with many Aboriginal people with a diverse range of views over the road extension.

Mr Collier said it was believed the project would not disturb the importance and significance of the area any more than had already occurred, pointing out that there had been other developments in the past, including road construction.

Meanwhile in response to a series of questions, Main Roads pointed out that Heritage Consent was provided by the minister with regard to the "general interest of the community".

The department said the Aboriginal heritage survey "influenced the project's preferred concept design".

Among the changes was the construction of a bridge between North Lake and Bibra Lake to "minimise impact on mythological values" and help maintain ecological and hydrological links.

Main Roads said other recommendations from traditional owners that were being implemented included the ongoing engagement with Aboriginal people during the life of the project, the use of heritage experts during construction, and the placement of plaques and artwork to commemorate heritage values.

The area constituting the two lakes remains a registered heritage site.

Greens MLC Lynn MacLaren said the opposition of Indigenous people was being hidden by the WA Government.

"We're very concerned that the voices of the traditional owners are being silenced in this debate, we believe that these traditional owners need to be heard," Ms McLaren said.

Ms MacLaren wrote to the Federal Environment Minister about the issue last month.

"The Minister for the Environment has an opportunity to call in more information if he believes on reasonable grounds that they don't have enough information, and we believe in this regard that the state has not provided the federal minister with enough information about the traditional owners' opposition to the project," she said.

"They were clear when they were consulted in 2010, they were clear when they were consulted in previous times, that opposition hasn't changed and the minister can't claim that there's support when there's no evidence that the majority of people supported it."